Generally, a navigation system for vehicles is associated with GPS satellites providing position information of the vehicle provides a map with a path to a destination to which the vehicle wishes to get, and displays position and moving speed of the vehicle driving on the path, thereby providing correct drive information to a user.
Such a navigation system provides a user who is not familiar with road information or is not yet well-informed of a road situation that becomes complicated more and more with urban development, with information on a precise path to a destination and a drive guide. Due to its convenience, a lot of drivers have the navigation system and the trend is that its distribution is rapidly extending. In the navigation system, further, a variety of service functions is being developed other than a simple path guide, including DMB (Digital Multimedia Broadcasting) reception and movie playback.
In addition, the navigation system is currently mounted in kinds of moving objects such as ships, aircrafts, and cars and is widely used to identify current position and speed of the moving objects or determine their moving path. Especially, the navigation system receives radios representing latitude, longitude and altitude from a plurality of GPS satellites and calculates a current location of the navigation system to visually display map information including its current position or audibly indicate the information.
Generally, the navigation system, which may be embodied in a form of a terminal for vehicles or a smart terminal such as a smart phone capable of receiving GPS signals, can perform functions such as including a storage medium such as a hard disk drive (HDD) that stores map data and a GPS receiver unit for receiving GPS signals, calculating an optimum drive path when a navigation function is required, and generating path data resulted from the calculation for presenting to a user.
Korean laid-open Patent No. 10-2011-0096321 suggests an apparatus and method for providing driving path using indoor map information. However, in case that a destination is an indoor location, there are problems that it is not possible to receive GPS signals using a conventional navigation system and to guide a user to a destination when an indoor map for the building is not stored.